The game is a reboot of id Software's Doom franchise. Doom 3 is set in 2145 on Mars, where a military-industrial conglomerate has set up a scientific research facility to research into fields such as teleportation, biological research and advanced weapons design. However, the teleportation experiments inadvertently open a gateway to Hell, resulting in a catastrophic invasion by demons. The player, an anonymous space marine, must fight through the base and find a way to stop the demons attacking Earth.[8]Doom 3 features an award-winning game engine, id Tech 4, which has since been licensed out to other developers,[9] and later released under the GNU General Public License in November 2011.

The game was a critical and commercial success for id Software; with more than 3.5 million copies of the game sold, it is the most successful game by the developer to date.[9][10] Critics praised the game's graphics and presentation,[11] although reviewers were divided by how close the gameplay was to that of the original Doom, focusing primarily on simply fighting through large numbers of enemy characters.[12] The game was followed by Resurrection of Evil, an expansion pack developed by Nerve Software in April 2005, while a Doom film loosely based on the series was released in October 2005. A series of novelizations of Doom 3, written by Matthew J. Costello, debuted in February 2008.[13] An expanded and improved BFG Edition was released in the fourth quarter of 2012.

Doom 3 is a story-driven action game played from a first-person perspective. As with previous Doom games, the main objective is to successfully pass through its levels, defeating a variety of enemy characters intent on killing the player's character. Doom 3's more story-centered approach, however, means that the player often encounters friendly non-player characters, who provide key plot information, objectives and inventory items. The game incorporates ten weapons for the player's use to survive, including conventional firearms and explosives such as a submachine gun, shotgun and grenades, experimental plasma weaponry, and the traditional BFG 9000 and chainsaw weapons of the Doom franchise.[14] Enemies come in multiple forms and with different abilities and tactics, but fall into two broad categories of either zombies or demons. Zombies are humans possessed by demonic forces, who attack the player's character using their hands and melee weapons or a variety of firearms, while demons are creatures from Hell, most of which attack using claws and spines, or by summoning plasma-based fireballs.[15] The corpses of demons are reduced to ashes after death, leaving no trace of their body behind.

A Revenant in Doom 3, attacking the player. The majority of the game takes place within the futuristic base.

The game's levels are fairly linear in nature and incorporate several horror elements, the most prominent of which is darkness.[16] This design choice is not only intended to foster feelings of apprehension and fear within the player, but also to create a more threatening game environment in which the player is less likely to see attacking enemies.[16] This aspect is further enhanced by the fact that the player must choose between holding a weapon and holding the flashlight (until the BFG editions released in 2012 made the "duct tape mod" a standard feature), forcing the player to choose between being able to see and having a readied weapon upon entering a room, which consequently leads to a more deliberate pace for the player.[16] In addition, the levels are regularly strewn with corpses, dismembered body parts and blood, sometimes used in conjunction with the game's lighting to disorient the player.[16]

Frequent radio transmissions through the player's communications device also add to the atmosphere, by broadcasting certain sounds and messages from non-player characters meant to unsettle the player. Early in the game, during and directly after the event that plunges the base into chaos, the player often hears the sounds of fighting, screaming and dying through their radio transmitter. The ambient sound is extended to the base itself through such things as hissing pipes, footsteps, and occasional jarringly loud noises from machinery or other sources. Often ambient sounds can be heard that resemble deep breathing, unexplained voices and demonic taunting from the game's antagonists.[8]

Early in the game, the player is provided with a personal data assistant (PDA). PDAs contain security clearance levels, allowing the player to access certain areas that are otherwise locked and off-limits. Additionally, the PDA can be used to read e-mails and play videos that the player's character acquires during the game. Whenever the player picks up any of the other PDAs found throughout the game, its contents are automatically downloaded to the player's own device. Other PDAs often contain e-mails and audio logs for other characters, which can provide useful information such as storage or door key codes, as well as significant plot details.[17]

Doom 3 was released with a four-player multiplayer element, featuring four game modes. However, the game's community created a modification to boost this to eight or sixteen players.[11][18][19] The Resurrection of Evil expansion would later officially increase the player limit to eight. The four game modes are all deathmatches. The standard deathmatch game mode involves each player moving around a level, collecting weaponry and killing the other players, with the player with the highest kills when the time runs out winning. A team variation of this involves the same principle. The third game mode is "last man standing", in which each player has a limited amount of respawns, with players losing a life when they are killed. Eventually, all but one player will be eliminated from the game, leaving the survivor as the winner. The final game mode is "tournament", in which two players fight each other while the other players watch as spectators. The victor of the battle remains in the arena, facing each other player one at a time until the winner of previous rounds is defeated. The loser then moves to the spectators and the new winner remains to fight the next player.[20] The Xbox version of Doom 3 also incorporates an additional two-player co-operative mode for the main single-player game.

As of April 15, 2010, The Xbox Live service was shut down, thus online multiplayer for original Xbox games through the service is no longer available.

Doom 3 is set in the year 2145. Much of the game's story and dialogue was created by author Matthew J. Costello.[8] According to the game's backstory, the Union Aerospace Corporation (UAC) has grown to become the largest corporate entity in existence, and has set up a research facility on Mars. At this base, the UAC are able to conduct research into several scientific areas, including advanced weapons development, biological research, space exploration and teleportation. On Mars, the UAC can perform its operations outside of legal and moral boundaries.[21] As the player progresses through the game, they learn that the employees on the base are unsettled due to a large number of incidents involving hearing voices, unexplained sightings and increasing cases of paranoia and insanity, often leading to fatal accidents with the facility's machinery. Rumors regarding the nature of experiments in the UAC's Delta Labs division are especially prevalent among the base's employees.

There are five main characters in Doom 3. The player assumes the role of an anonymous space marinecorporal who has just arrived on the UAC's Mars base. The player's non-commissioned officer in-charge is Master Sergeant Thomas Kelly, voiced by Neil Ross,[22] who gives the player objectives and advice over the player's radio for the first half of the game. The antagonist in the story is Dr. Malcolm Betruger, head scientist of the UAC's enigmatic Delta Labs division, who is revealed to be working in collaboration with the forces of Hell to cause the subjugation of humanity. Betruger's demonic voice, provided by Philip L. Clarke,[22] frequently taunts the player as the game progresses. The final two principal characters are Elliott Swann and Jack Campbell. Swann, voiced by Charles Dennis,[22] is a representative of the UAC's board of directors, sent to check up on Betruger's research as well as investigate the rising number of accidents on the Mars base after a request for assistance from a whistleblower. He is almost always accompanied by Campbell, another space marine who acts as Swann's bodyguard and is armed with a BFG 9000. Campbell is voiced by Andy Chanley.[22] Swann and Campbell are often shown in the game to be a few steps ahead of the player, but cannot be reached and directly communicated with until late in the game.[8] The game also incorporates a large host of minor characters who add details to the story or assist the player in certain segments. The player encounters multiple scientists involved in the various research and development programs and archaeological digs through the UAC base, as well as fellow marines and security guards. Civilian employees engaged in bureaucratic work and maintenance workers are also seen.

Doom 3 acts as a prequel to the first game. The story of Doom 3 is conveyed through in-game dialogue and cut scenes, as well as e-mails, audio logs and video files found throughout the game. The game opens with UAC board member Elliott Swann and his bodyguard Jack Campbell arriving at Mars City, the main access to the UAC's Mars base, disembarking from an Earth transport, with the player's anonymous marine just behind them. Swann and Campbell, here to investigate multiple incidents, have a heated conference meeting with the man in charge of the Mars laboratories, Dr. Malcolm Betruger[23] while the marine heads to Master Sergeant Thomas Kelly for orders. Kelly gives the marine instructions to find a scientist from the Delta Labs who has gone missing.[24] The marine finds the scientist in a nearby decommissioned communications facility, where he is frantically trying to send a warning to the UAC on Earth about Betruger's teleportation experiments.[25] However, as he tries to explain the situation to the marine, another teleportation test takes place and loses containment, at which point the entire Mars base is swept with an unnatural shockwave. This transforms most of the base's personnel into zombies as the forces of Hell invade through the teleporter's portal.

Much of Doom 3, such as this section in the Delta Labs, was planned using storyboards

Now forced to fend off attacks from zombified base personnel and the demons from Hell, the marine returns to Mars City, where Kelly remotely gives the marine orders to link up with another squad of marines (Bravo Team) and get a transmission card containing a distress call to the main communications facility to call for reinforcements. As the marine progresses through the base, he learns that Swann and Campbell have survived, and are also en route to the communications facility to prevent any messages being sent in hope of containing the situation on Mars. The marine squad is ambushed by demons and slaughtered in the EnPro Plant,[26] and although the marine recovers the transmission card, he is too late to prevent the bulk of equipment at the communications facility being destroyed by Campbell. Kelly, however, directs the marine to a backup system,[27] where the marine is given the choice of whether to obey Kelly's orders to send for reinforcements, or accept Swann's argument to keep Mars isolated until the exact nature of the invasion is understood, so as not to endanger Earth.[28] The marine is told to go to the Delta Labs by Kelly or Swann, depending on whether the transmission is sent or not.

On the way to the Delta Labs, the marine is contacted by Betruger, who is now clearly shown to be working in cooperation with Hell in order to invade Earth. If the marine did not send the distress call to Earth, Betruger does so himself, hoping to use the ships bringing reinforcements to transport the demons to Earth.[29] Betruger then unsuccessfully attempts to kill the marine using the toxic gases in the base's recycling facilities. Upon arriving at the Delta Labs, the marine learns of the details behind the teleportation experiments, expeditions into Hell to retrieve specimens and Betruger's increasing obsession with the tests, as well as of an archaeological dig under the surface of Mars. The dig is excavating the ruins of an ancient civilization discovered on Mars, and has produced a relic known as the Soul Cube. According to a scientist the marine finds alive in the labs, the Soul Cube is a weapon created by the ancient civilization to defend against the forces of Hell. The scientist also reveals that the invasion began when Betruger took the Soul Cube into the portal at the beginning of the game, depositing it in Hell.[30] The marine pursues Betruger through the labs, but is pulled into the main teleportation portal after being lured into a trap by Betruger.

The portal takes the marine directly into Hell, where he proceeds to fight his way through the large number of demons to the Soul Cube, defeating its demonic guardian. The marine is then able to reinitialize the teleportation equipment left by research expeditions into Hell and return to the Delta Labs. Betruger, however, tells the marine that although the main UAC teleporter has been destroyed, Hell is opening a Hellmouth on Mars, capable of bringing millions of demons to Mars.[31] Further in the Delta Labs, the marine encounters the injured Swann. Swann informs the marine that Kelly has been working with Hell for possibly the whole time, and has been transformed by the demons.[32] Telling the marine that Campbell has gone after Kelly, Swann gives the marine his PDA containing information on the location on the Hellmouth under the surface of Mars and assures him that he will try to make his way out of the base alone.

However, when the marine catches up with Campbell in the central computer processing sector of the base, Campbell is mortally wounded and only has enough strength to say that Kelly has taken Campbell's BFG 9000 weapon before expiring.[33] Kelly then begins to taunt the marine in a demonic voice.[34] The marine eventually faces off with Kelly in the central computer core, revealing Kelly as a cybernetic human grafted onto a tank-like base. The marine is able to kill Kelly and takes the BFG 9000 before proceeding deeper under the Martian surface to Site 3, the archaeological dig site where the Soul Cube was unearthed. At the primary excavation site, the marine discovers the Hellmouth, defended by Hell's mightiest warrior, the Cyberdemon. Using the Soul Cube, the marine defeats the Cyberdemon in combat, and the Soul Cube then seals the Hellmouth. The ending cut scene shows the reinforcements from Earth arriving at the base to discover the carnage. They find the marine alive, but discover that Swann has died. They are, however, unable to locate Betruger, who in the final scene is shown in Hell, reincarnated as a dragon-like demon.[35]

The game engine powering Doom 3 was created by John Carmack, who also spurred the initial planning of the project

In June 2000, id Software's game engine designer John Carmack posted an internal company plan announcing a remake of Doom using next generation technology.[36] This plan revealed controversy had been growing within id Software over remaking Doom. Kevin Cloud and Adrian Carmack, two of id Software's owners, were always strongly opposed to remaking Doom, believing that id was going back to the same formulas and properties too often. However, after the positive reception to Return to Castle Wolfenstein and the latest improvements in rendering technology, most of the employees agreed that a remake was the right idea and presented the two owners with an ultimatum: allow them to remake Doom or fire them. After the reasonably amicable confrontation (although artist Paul Steed, one of the instigators, was fired in retaliation),[36] the agreement to work on Doom 3 was made. id Software began development on Doom 3 in late 2000, immediately after finishing Quake III: Team Arena.[37] In 2001, it was first shown to the public at Macworld Conference & Expo in Tokyo[38] and was later demonstrated at E3 2002, where a fifteen-minute gameplay demo was shown. It won five awards at E3 that year.[39]

Early in Doom 3's development, Trent Reznor of the band Nine Inch Nails, a fan of the Doom games,[40] was set to compose the music and sound effects to Doom 3. However, due to "time, money and bad management",[40] none of Trent Reznor's sound effects or music made the final product. Eventually, Nine Inch Nails' former drummer, Chris Vrenna, composed and performed the game's theme song.[41]

We never really did come to an actual agreement with Trent. The original idea was just for him to do all of the sound design for the game. I don't think Trent anticipated how long and how involved that process was and what is involved in game design versus what he does in the music and production side. It just wasn't a good mix with how much time it was going to take him, the value it was going to provide to the game, and what we could afford to pay. Trent's a popular guy. He's a rock star, and his time is valued in rock star dollars.

Doom 3 was also intended to be more storyline focused than previous id titles, as was demonstrated by the developers' conscious effort to have more professional voice acting.[43] Late in 2002, two employees at ATI Technologies leaked a development version of Doom 3 onto the Internet.[44] One year later, a new trailer was shown at E3 2003 and soon afterwards id Software's website was updated to showcase Doom 3 as an upcoming project, although it was also announced that Doom 3 would not be ready for the 2003 holiday season. According to John Carmack, the development took longer than expected.

The shadowing effects of the unified lighting and shadowing engine applied on a group of zombies

According to John Carmack, the lead graphics engine developer at id Software, the technology of Doom 3 was supported by three primary features: unified lighting and shadowing, complex animations and scripting that showed real-time with fully dynamic per-pixel lighting and stencil shadowing, and GUI surfaces that add extra interactivity to the game.[46] The key advance of the id Tech 4 graphics engine developed for Doom 3 is the unified lighting and shadowing. Rather than computing or rendering lightmaps during map creation and saving that information in the map data, most light sources are computed in real-time. This allows lights to cast shadows even on non-static objects such as monsters and machinery, which was impossible with static non-directional lightmaps. A shortcoming of this approach is the engine's inability to render soft shadows and global illumination.[46]

To increase the interactivity with the game-world, id Software designed hundreds of high-resolution animated screens for in-game computers. Rather than using a simple "use key" to operate these computers, the crosshair acts as a mouse cursor over the screens allowing the player to use a computer in the game world. This allows for in-game computer terminal to perform more than one function, from operating security door codes, activating machinery, toggling lights or unlocking weapons lockers. According to the Doom 3 manual, GUI designer Patrick Duffy wrote over 500,000 lines of script code, and generated more than 25,000 image files to create all of the graphical interfaces, computer screens, and displays throughout Doom 3.[47] Other important features of the game engine are normal mapping and specular highlighting of textures, realistic handling of object physics, dynamic, ambient soundtrack, and multi-channel sound. Doom 3 on Xbox supports 480p widescreen video display resolution and Dolby Digital 5.1 surround sound.[48]

Doom 3 achieved gold status on July 14, 2004[49] and a Mac OS X release was confirmed the next day.[50]Doom 3 was released in the United States on August 3, 2004 and to the rest of the world on August 13. Due to high demand, the game was made available at select outlets at midnight on the date of release. Additionally, a Linux version was released on October 4, 2004 by Timothee Besset. The Mac OS X version was released on March 14, 2005 and on February 20, 2006 the patch 1.3 Rev A included a universal binary, adding support for Mac OS X on the x86 architecture.[51] Finally, the modified Xbox conversion was released on April 3, 2005, featuring a limited steel book edition which included Ultimate Doom and Doom 2.

A week before the game's release, it became known that an agreement to include EAX audio technology in Doom 3 reached by id Software and Creative Labs was heavily influenced by a software patent owned by the latter company. The patent dealt with a technique for rendering shadows called Carmack's Reverse, which was developed independently by both John Carmack and programmers at Creative Labs. id Software would have placed themselves under legal liability for using the technique in the finished game, so to defuse the issue, id Software agreed to license Creative Labs sound technologies in exchange for indemnification against lawsuits.[52]

During the keynote address at QuakeCon 2011, John Carmack announced that the source code for the Doom 3 engine would be released.[53] The source code was open-sourced under the GPL on November 22, 2011. It contains minor tweaks to the shadow rendering code to avoid potential patent infringement with a patent held by Creative Labs. Art assets such as 3D models, music, sound effects etc. remain subject to the EULA.[5]

On April 3, 2005, eight months after the release of Doom 3, id Software released an expansion pack for Doom 3 on Windows.[54] The expansion, entitled Resurrection of Evil, was developed by Nerve Software, a company that had partnered with id Software on several other projects, including Return to Castle Wolfenstein and the Xbox conversion of Doom. Once again published by Activision, a Linux version was released on May 24, 2005, and an Xbox version followed on October 5, 2005.[55] The expansion featured a new twelve-level single player campaign, set two years after the original storyline, as well as three new weapons, one of which is geared towards manipulating the physics in the game. Several new enemy characters were also introduced. Multiplayer gameplay was enhanced, officially increasing the player limit to eight and adding new game modes such as capture the flag.[56]Resurrection of Evil's reception was not as positive as it had been for Doom 3, but still received generally favorable reviews from the industry's critics.[57]

A re-release of Doom 3 called Doom 3: BFG Edition, which was published by Bethesda Softworks, was released on October 15, 2012, in Australia, October 16, 2012 in North America,[58] October 19, 2012 in Europe and November 22, 2012 in Japan for PC, PlayStation 3 and Xbox 360. The BFG Edition features enhanced graphics, better sound with more horror effects, a checkpoint save system, and support for 3D displays and HMDs. The game also includes the previous expansion Resurrection of Evil and a new single-player expansion pack called The Lost Mission. Additionally, it includes copies of the original Doom (the Ultimate Doom edition with the add-on fourth episode, "Thy Flesh Consumed"), and Doom II with the expansion No Rest for the Living, previously available for the Xbox 360. The BFG Edition also features the ability to use the flashlight while holding a weapon, in the form of the so-called armor-mounted flashlight.[59] The PC version of Doom 3: BFG Edition requires the Steam client and a valid Steam account for installation, play and achievements. The versions of Doom I and II released with BFG have been censored in some ways. And in doom 3 with the noticeable removal of the co-op campaign for single player campaign.[60]

Doom 3 received a favorable reception from critics, with the PC version of the game holding an 87 percent score[70] and an 88 percent score[68] at the review compilation sites Metacritic and GameRankings respectively. Much praise was given to the quality of Doom 3's graphics and presentation; GameSpot described the game's environments as "convincingly lifelike, densely atmospheric, and surprisingly expansive",[19] while PC Gamer UK described the graphics and non-player character modeling and animation as simply "flawless", stating that Doom 3 signalled the return of the Doom franchise to the forefront of the computer and video game industry, eleven years after the release of the original Doom.[16]IGN's Dan Adams noted that the game's presentation comprised a remarkably high proportion of the game, stating that "without the atmosphere, Doom 3 is a plain shooter that hearkens back to those of the '90s."[18] In addition, several reviewers praised id Software for making the game still look surprisingly good even on lower graphics levels.[12][18]

A number of reviewers also praised the attention paid to the game's premise and setting; GameSpot's Greg Kasavin described getting "the impression that Doom 3 takes place in a fully realized world"[19] while IGN noted that "the UAC base also has a very worn and lived-in feel that adds to the realism."[18]Eurogamer in particular pointed out that the game's opening sequence "feels like a fitting tribute to the excellent ideas" of Valve Software's genre-defining Half-Life.[62]

Many reviewers noted that Doom 3 stuck with a similar "run and gun" gameplay style that was successful with its predecessors, and the game was alternately praised and criticized for this element. Several reviews were critical of a perceived repetitiveness in gameplay after a while.[12][19] In addition, the game's artificial intelligence was not regarded as particularly challenging, with GameSpot noting that "enemies follow the same sorts of predictable patterns that [players] may remember from previous Doom games"[19] while GameSpy stated the way enemies would spawn to attack the player was "gimmicky"; the reviewer noted that players would realize that picking up a lone armor vest would cause a variety of zombies to emerge from hidden compartments in the dark.[11] In addition, several reviewers noted that the game's methods of conveying the story were "ineffectual", compounded by the lack of an identity for the player character.[19] Finally, the game's multiplayer was seen as lacking in innovation, with its low player limits and small number of game modes, particularly in contrast to id Software's influential Quake III Arena.[11][18][19]

The Xbox version of Doom 3 received a similar level of critical support, holding a score of 88 percent on Metacritic[71] and an 87.7 percent score on GameRankings.[69] The game was praised and faulted on many of the same issues as the PC version,[64] although the game was praised for maintaining smooth and user-friendly controls on a gamepad, as well as for including a two player co-operative multiplayer mode, which IGN described as "worth the price of admission alone."[66] However, some criticism was directed towards slow-downs in play due to the game engine, despite being scaled down for the Xbox, still being demanding on the Xbox hardware.[66]

In early 2008, a new series of Doom novels by Matthew J. Costello were published, an author who had worked on the story and scripts for Doom 3 and Resurrection of Evil; previous Doom novels had expanded the storyline of the original two Doom games. The series of books aim to novelize the story of Doom 3, with the first installment, Worlds on Fire, published on February 26, 2008.[13] The second book in the series, Maelstrom, was released in March 2009.[75]

On November 22, 2011, the source code of the Doom 3 engine was released under the GPL, but the game's artwork content still remains under the EULA. A later source code drop also included the changes made for the BFG Edition, allowing the re-release to potentially be ported to other previously unsupported platforms such as Linux and OS X,[76] and such a port was eventually released.[77]

id Software eventually went on to do another remake, this time following the series' original roots in minimal storytelling and fast-paced action. Simply titled Doom and powered by the new id Tech 6, the game was released on May 13, 2016 by Bethesda Softworks for Microsoft Windows, Xbox One, and PlayStation 4 with cross-platform support in its "Snapmap" multiplayer mode. Development was announced in May 2008, then slated to run on the id Tech 5 engine and initially titled as Doom 4.[80]

The 2016 release marks a second reboot for the Doom series following the release of Doom 3, in 2004.

^id Software (2004). Doom 3 (manual). p. 16. Doom 3 lore – Tim Willits, the lead designer on Doom 3, started his career making maps for the original Doom and releasing them on the internet for free. id liked his work and hired him as a designer in 1995.

^id Software. Doom 3. PC. Activision. Level/area: Mars City. The Union Aerospace Corporation is the largest corporate entity in existence. Originally focused on weapons and defense contracts, new ventures have expanded into biological research, space exploration, and other scientific endeavors. With unlimited funds and the ability to engage in research outside of moral and legal obligations, the UAC controls the most advanced technology ever conceived.

^id Software. Doom 3. PC. Activision. Level/area: Mars City. Elliott Swann: I will need full access, Doctor Betruger, Delta included. I won't have any difficulties doing that will I? / Malcolm Betruger: Only if you get lost Swann. Just stay out of my way. Amazing things will happen here soon, you just wait.

^id Software. Doom 3. PC. Activision. Level/area: Marine HQ, Mars City. Thomas Kelly: Now, here's the situation. Another member of the science team's gone missing. As you're the ranking FNG, you get to find him. I want you to check out the old decommissioned comm facility, we heard he might be headed that way.

^id Software. Doom 3. PC. Activision. Level/area: Old Comn Main, Mars City Underground. Jonathan Ishii: Huh? No, no, please... you must let me get this communication out. They have to warned while there is still time. I can't let... I... You don't know what I've seen! You can't possibly understand or comprehend. The Devil is real! I know... I built his cage.

^id Software. Doom 3. PC. Activision. Level/area: EnPro Plant. Thomas Kelly: Marine, Bravo Team is down; their operational status is unknown. They were carrying a military transmission card. It's vital that you retrieve that card as it contains encoded data needed to send a distress signal to the fleet. You're the last hope to get reinforcements. Find that card and find it fast.

^id Software. Doom 3. PC. Activision. Level/area: Main Communications Room, Communications. Thomas Kelly: Marine, Delta system computers are showing all off-base communication down. It's that fool Swann isn't it? You're going to have to find another way to send that message. Make your way to the satellite room and manually establish a link from there.

^id Software. Doom 3. PC. Activision. Level/area: Satellite Control Center, Communications. Elliott Swann: Marine? Can you hear me? Back off from that console. Do not call for reinforcements, we do not know what the hell is going on here, and until we do this area remains under UAC control. Cancel that transmission.

^id Software. Doom 3. PC. Activision. Level/area: Pumpstation1 B, Recycling Sector 2. Malcolm Betruger: Making progress are we? And in such a hurry to find us... to find... me. There is no need to rush, I am everywhere, and everything here is mine. It's a pity you did not alert the fleet, but it is of no consequence—I'll alert them myself. They will come to the rescue and be consumed by my legion. We will use their ships to bring this Hell to Earth! You won't live to see it, and you will die long before you have a chance to warn them.

^id Software. Doom 3. PC. Activision. Level/area: Teleporter Control Lab, Delta Labs Sector 2A. Ian McCormick: And then Betruger: he went through the portal himself. I don't know what he was thinking. It was an unscheduled trip and he just went and we couldn't stop him. And when he came back he had changed. He sounded and looked the same, but... I don't know, he was just... different. And then he did the unthinkable: he took the Soul Cube—the device that was discovered in the ruins—into the portal. The portal stabilizers just started to fail, and then, living hell erupted into the base.

^id Software. Doom 3. PC. Activision. Level/area: Delta Complex. Malcolm Betruger: You are too late: Hell no longer needs that portal to enter this world! The invasion you saw was only the first wave, the Hell Gate is capable of sending millions of my children into your world.

^id Softwar]. Doom 3. PC. Activision. Level/area: Delta Authority Lobby, Delta Complex. Elliott Swann: Still alive? Looks like you might be on your own: Sarge is gone. They've got to him. I don't know how long he's been working against us. He's... no longer human. Campbell went after him. He's got to be stopped.

^id Software (2004). Doom 3 (manual). p. 11. Doom 3 lore – There were over 500,000 lines of script code written and over 25,000 image files generated in the process of creating all of the graphical interfaces, computer screens, and displays throughout Doom 3